Between 84 million and 75 million years ago, near the end of the Cretaceous, part of the land now known as the Gobi Desert was host to a variety of raptors. There were two species of Velociraptor, a similar predator named Tsaagan mangas, a tiny feathered dinosaur called Mahakala omnogovae, and, as just announced in the journal Zootaxa, a previously unknown type represented by an exquisitely-preserved specimen. It is called Linheraptor exquisitus.
As described by paleontologists Xing Xu, Jonah Choiniere, Michael Pittman, Qingwei Tan, Dong Xiao, Zhiquan Li, Lin Tan, James Clark, Mark Norell, David Hone and Corwin Sullivan, Linheraptor was a relatively small predatory dinosaur most closely related to Tsaagan. Outside of some small differences in the skull, such as the size and placement of small holes (called fenestrae) towards the front of the skull, the two appear to represent a group of unique dromaeosaurs which, while close cousins of their neighbor Velociraptor, lacked some of the specialized characteristics which distinguish their more famous relative.
Further research on Linheraptor has been planned, but I find it especially interesting that the famous Djadokhta Formation (home of the Flaming Cliffs) has yielded another predatory dinosaur. What could it have been eating, and how did it avoid competition with the other raptors in the area? Famous specimens such as the "fighting dinosaurs" have confirmed that some of the raptors fed on Protoceratops, and the numerous kinds of small mammals which lived in the area were probably prey, but the general scheme of "who ate whom" is still incompletely known. The preservation in the Djadokhta Formation is so good, however, that scientists have been able to get a well-defined look into this part of Earth's history, and with any luck further discoveries will tell us more about the ecology of the area during the time of Linheraptor.
David Hone, one of the authors of the new Linheraptor paper, has more about the find at his blog Archosaur Musings.
XING XU, JONAH CHOINIERE, MICHAEL PITTMAN, QINGWEI TAN, DONG XIAO,, & ZHIQUAN LI, LIN TAN, JAMES M. CLARK, MARK A. NORELL, DAVID W. E. HONE, CORWIN SULLIVAN (2010). A new dromaeosaurid (Dinosauria: Theropoda) from the Upper Cretaceous Wulansuhai Formation of Inner Mongolia, China Zootaxa, 1-9